ATI damper and INA Alternator pulley

With 180k+, and 18 years on the stock harmonic damper, it was time for replacement. Splurged a bit, and got the VAC motorsports version by ATI. I am a sucker for heavy duty upgrades.

While preparing and researching, I saw some places talking about the alternator pulley. Some links:
https://www.e46fanatics.com/threads/...d-info.806821/
https://www.youtube.com/watch?v=9beaAjKLBnY <- good voice on that dude
https://www.youtube.com/watch?v=gXa384YJdL0 <- explainer video

I decided to give it a go. Yes, the M54 is already smooth, but this can't hurt.

This tool helps with the installation: http://www.metalnerd.com/catalog/pro...5e586d88a2e97d

Per the videos, the pulley increases the alternator efficiency, but it is also 12% bigger, which likely negates that with the under drive effect.

The 3mm bigger radius is easily within the belt's and tensioner's tolerances; I dare say it is plug and play.

The result. I immediately noticed a smoother running engine. Climbs the RPMs faster, too.
Did not check fuel economy yet, but I saw a small bump in the instrument cluster; maybe 1 MPG after 1/2 a tank. And I was not gentle with it as you can imagine.

BTW, there is another pulley mentioned here: https://www.e46fanatics.com/threads/...-list.1249269/

That did not fit my car, maybe it will fit some models, but as I had my old alternator out - 12317519620, I compared the pulley when it arrived and there is no way it will fit. VW part 022903119C in the first post fits.

Will post here again if I run into any issues at all.

Maybe someone can install only the pulley and share their experience. I posted two parts here, so cannot attribute the benefits to either of the parts with confidence. The price we pay for "might as well while we are in there".

Thanks for the report. I've had the INA pulley in storage for over 2 years now and just never get around to installing it. I have no way of getting the alternator pulley off with my hand tools. Maybe I'll bring it to a shop to finally get it done. Your post has definitely given me some extra motivation.

My main motivation is to reduce the oil pump issues on the M54. I still need to upgrade the pump regardless but the overrunning pulley is an additional layer of safety. Not looking forward to having to replace it periodically as a wear item though.

Yes, good to have that, even though the ZHP has a better oil pump nut than the usual M54.
I used the VAC Motorsports Oil Pump Upgrade Kit and put in their Oil Pan Baffle at the same time.
Good insurance if/when you track the car. Mine has the ESS TS2, so I really don't want it dying on me.
Oh, and another ingredient was the spring on the cam chain tensioner.
It was not making noise, but I bet that too had an effect on how the car runs. Every little bit helps.

I may have goofed up the math of the under drive effect for pulley size. The radius of the stock pulley is 25mm. The radius of INA one is 28mm. The circumference is what we should compare, not the radius. The circumference is calculated as Pi x the radius squared. To simplify we do 28^2 / 25^2 = 1.25. It takes 5 rotations on the new pulley to equal 4 on the stock. That is a 25% under drive effect, I doubt the pulley is 25% more efficient. Let's assume it is 10% if we are generous FWIW, I have had no electrical issues so far. Maybe as I am running the 120 amp alternator it helps. I know our cars accept 90 or 120 amp alternators. Best be sure anyone doing this have a 120 amp alternator. So at the worst case with this pulley they will have 120*.8 = 96 amp. And if the pulley does help at 10%, then you have 96*1.1 = 106 amp.

Or something like that ;-)

I can confirm the 90A alternator, 12317501687, won't fit / work with the pulley. That is what my Z3 had and it did not work. Fortunately, I put in the older one from my E46. So be sure to have a 120A Alternator. Bosch 12317501690 is the one you want.

How do you tell the difference without removing the alternator?

Mine, then 90A Valeo had the air duct, which was clogged, BTW. The Bosch one does not have an air duct. Also, the connection plug is different on the alternators. The 120A alternator has a connection that looks like the on here: https://www.bmotorsports.com/shop/pr...oducts_id/4105 - CONN-85956

If your car came with the 90A one, you will also need to get that connection pigtail else you won't be able to connect the 120 Alternator.

Here is the picture of the Valeo:
Attachment 39384

Another thing you will notice if you take the pulley off, the 120A will have a visible dark circle behind the pulley. The 90A will not, it will have metal close to the shaft where you mount the pulley. If you try to put the 1.8T pulley on, 2 things will happen. 1), it won't turn, 2) it won't align with the belt. Wish I took more pictures.

BTW, the Z3 likes it too, no surprise there. It's M54B25 - higher compression ratio. and a 3.46 diff. It revs fast and smooth.

Let me know if you want more pictures of the 90A alternator, I still have it.

Sorry for the late reply. No idea why I am not getting notifications. I'll check my settings.

Here is what the 90A pulley looks like.Attachment 39385

I hope this helps.

Thanks for the pics, I'll have to take a closer look when I tackle my power steering lines again.